GODHANDS

Description

An application that lets you interact with 3D objects in space! Originally a final year project for the Digital Media Programming course (CMPS230) at the American University of Beirut advised by Dr. Maha El Choubassi

You load an object (.obj) file, you turn on your camera, and move around, the object will react according to your movements.

License

Copyright (C) 2013 George Zakhour and Remi Nassar

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Dependecies

For Debian user, processing (to connect to the camera depends on the following packages)

• libgstreamer-plugins-base0.10-dev
• libgstfarsight0.10-dev
• libgstreamer0.10-dev
• If sound is not playing please read this temporary fix here

Documentation

The documentation of this program is provided as follow: we will list all the libraries that were used. Foreach library there is a brief description of it, a list of all the methods that are accessible to the user along a brief description of the parameters, the return and the goal of it. As well, a brief example is used to illustrate how to use this class.

The projects includes the following:

• Anaglyph Library
• OBJ Library
• SimpleMotionDetection
• ScrollBar

###Anaglyph Library The library consists of a class Anaglyph that creates anaglyph images provided two PImages

The public methods in that class are:

• Anaglyph(PImage, PImage) (Constructor) sets the object
• updateLeft(PImage) updates the left-eye image
• updateRight(PImage) updates the right-eye image
• getRight() returns the right-eye image
• getLeft() returns the left-eye image
• render() creates the anaglyph version of the two images and returns it
• createBW(PImage) applies the Luminance grayscale algorithm on the image supplied and returns the grayscale version

PImage left = loadImage("left.jpg");
PImage right = loadImage("right.jpg");
Anaglyph g = new Anaglyph(left,right);

void setup() {
    size(left.width, left.height);
    noLoop();
}
void draw() {
    image(g.render(),0,0);
}

###OBJ Library The library consists of a class OBJ that is a wrapper class to PShape provided by processing. As well it adds to it the ability to boost the object giving a certain acceleration.

The public methods in that class are:

• OBJ(String) (Constructor) will load that shape to the PShape
• getShape() returns the shape
• boost(PVector) will add acceleration to the object
• rotateUp() will rotate the object up
• rotateDown() will rotate the object down
• rotateLeft() will rotate the object left
• rotateRight() will rotate the object right
• update() will update the rotation of the cube depending on the acceleration of the object

OBJ o;

void setup() {
    o = new OBJ("/path/to/model.obj"); // load the 3D model
    size(300, 300, P3D); // to make it 3D
}

void draw() {
    background(0);
    noStroke();
    directionalLight(120, 120, 120, 0, 0, -1);
    ambientLight(120, 120, 120);
    translate(width/2, height/2);
    scale(80);
    shape(j.getShape(),0,0);
}

###Simple Motion Detection The library consists of a class SimpleMotionDetection that handles in a very minimalistic and simple way motion detection in 2 images given. The library, given the old frame and current one, checks pixel by pixel where the colors are not equal within a range, if they are not equal then motion happens.

The public methods in that class are:

• SimpleMotionDetection(int) (Constructor) will create the engine, int is how strict the engine should be: 0 very strict, 255 least strict.
• setPrevious(PImage) sets the previous variable, that is the last frame to compare with the current one
• setCurrent(PImage) sets the current variable, the way that will be compared the previous frame
• setTreshold(int) change the strictness of the engine
• getPrevious() returns the previous image (PImage)
• getCurrent() returns the current image (PImage)
• getTreshold() returns the strictness of the engine (int)
• getDiff() returns the dithered image that represents in black pixels where the motion happened
• getMotionLocation() returns the location of the motion. The image checks the location of all the motion pixels and then gets the average location between them
• getOverallMotionVector() returns the motion vector of the motion that occured

import processing.video.*;
Capture camera;
SimpleMotionDetection md;
PImage prev;

void setup() {
        camera = new Capture(this, 320, 240, 30);
        camera.start();
        md = new SimpleMotionDetection(50);
        prev = createImage(camera.width, camera.height, RGB);
        size(640, 240);
}

void draw() {
        if(camera.available()) {
                prev = createImage(camera.width, camera.height, RGB);
                prev.copy(camera, 0, 0, camera.width, camera.height, 0, 0,
                          camera.width, camera.height);
                prev.updatePixels();
                camera.read();
        }
        md.setPrevious(prev);
        md.setCurrent(camera);

        image(md.getDiff(), 0, 0);
        image(camera, 320, 0);

        PVector loc = md.getMotionLocation();
        noStroke();
        fill(color(255, 0, 0));
        ellipse(320+loc.x, loc.y);
}

###Scrollbar The library consists of a class called ScrollBar that handles minimalistic scroll bars. Given the label the width, the maximum value and the position the library will draw a bar where the user can select values from.

The public methods in the class are:

• ScrollBar(int,int,String,float,int) (Constructor) takes the x position, y position, the label of the bar, the maximum value and the width of the bar
• getLabel() returns the label used
• getValue() returns the current value that the bar represents
• setLabel(String) changes the label to a given one
• setValue(float) changes the value to a new one
• show() displays the bar

ScrollBar sensitivity;

void setup() {
    sensitivity = new ScrollBar(10, 10, "Sensitivity", 10, 100);
    sensitivity.setValue(3); // default value

    size(200, 400);
}

void draw() {
    sensitivity.show();
    println("Current sensitivity is: "+sensitivity.getValue());
}

Demo Video

A youtube demonstration can be found here

Contributors

• George Zakhour gez00@aub.edu.lb
• Remi Nassar rmn30@aub.edu.lb

Credits

• The SimpleMotionDetection class was inspired from Daniel Shiffman's Chapter 16: Example 16-23: Simple Motion Detection